The City of Muscle Shoals, Alabama, et al. v. 3M Company, et al.

SSP&A was retained by counsel for the Plaintiffs to evaluate and opine on PFAS contamination from the defendants’ facilities on the Tennessee River, as well as the effects of the ongoing remediation efforts occurring in and around Morgan County, Alabama on the City of Muscle Shoals and the Muscle Shoals Utility Board (MSUB).

Direct discharges of PFAS—including perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS)— into the Tennessee River upstream of Muscle Shoals, Alabama occurred through various transport routes (e.g., wastewater, stormwater, sediments), and often contained PFOA and PFOS concentrations in the hundreds of thousands of parts per trillion) Indirect discharges of PFAS into the Tennessee River upstream of Muscle Shoals include groundwater discharge and porewater in river bottom sediments by desorption (releasing) from contaminated sediments.

SSP&A evaluated detailed water quality sampling for PFAS in the Tennessee River from November 2021, PFAS concentrations in National Pollution Discharge Elimination System (NPDES) discharges from the 3M property and the Daiken property and PFAS water quality results from intake water at the MSUB’s water intake. In order to meet proposed maximum contaminant levels at MSUB’s water intake, SSP&A concluded that the annual flux of PFOA and PFOS would need to be reduced by several hundred kilograms per year and that current proposed remedial efforts are insufficient for addressing continued releases of PFAS to surface water via sediment porewater and, to a lesser extent, desorption from entrained/disturbed sediments.